牛乳的过氧化物酶处理与凝固型酸奶品质的变化

利用辣根过氧化物酶和阿魏酸处理牛乳并制备凝固型酸奶,采用质构仪和流变仪分别对不同酸奶样品的质构和流变特性进行对比研究。研究结果表明,辣根过氧化物酶、阿魏酸和明胶的添加对酸奶样品的主要成分组成没有影响,但对酸奶质构和流变特性的影响较大。与对照样相比,添加明胶、添加酶和阿魏酸、添加酶酸奶样品的硬度分别增加38.03%、34.07%和17.08%,黏度分别增加45.13%、40.85%和28.36%,而乳清析出率分别降低12.02%、6.28%和3.41%。同时,酸奶的表观黏度、触变性和粘弹性也都增加,增幅最大者为添加明胶酸奶样品,其次是添加酶和阿魏酸的酸奶样品,增幅最小的是添加酶的酸奶样品。研究结果显示利用辣根过氧化物酶、阿魏酸处理牛乳可以改善凝固型酸奶的品质。

Treatment of Bovine Milk by Horseradish Peroxidase and Its Impact on the Quality of Set-yoghurt

Bovine milk was treated with horseradish peroxidase or/and ferulic acid,and used to prepare set-yoghurt.The textural and rheological properties of the yoghurt samples prepared were measured with Texture Profile Analyzer and Rheometer and compared to that of control.The results showed that treatment of bovine milk with horseradish peroxidase or/and ferulic acid did not impact the main compositions of the yoghurt samples,but clear influence on the texture and rheology.Compared to that of control,the hardness or the adhesiveness of the yoghurt samples with gelatin addition,horseradish peroxidase treatment,or horseradish peroxidase plus ferulic acid treatment had an increase of 38.03,34.07 and 17.08%,or 45.13,40.85 and 28.36%,respectively,while the syneresis of these samples had a decrease of 12.02,6.28 and 3.41%,respectively.Also,the apparent viscosities,thixotropy and viscoelastic behaviors of these samples were in the order of the yoghurt with gelatin addition,the yoghurt with horseradish peroxidase plus ferulic acid treatment,the yoghurt samples with horseradish peroxidase treatment,control.Our results stated that treatment of bovine milk with horseradish peroxidase or/and ferulic acid had a beneficial effect on the quality of set-yoghurt prepared.